Stock-Based Compensation (Schedule of Unrecognized Stock-based Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Months
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 31,048
Expected amortization period (months)	32
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	23,868
Expected amortization period (months)	30
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	5,475
Expected amortization period (months)	37
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 1,705
Expected amortization period (months)	36